Come on John, they're all goosed on eBay! This same scenario has been played out on the forum loads of times over the years.
Even when I buy a complete deck on ebay, I always assume that the cartridge is goosed.........and I'm not often wrong!!
If you're not happy with you MMC4, why not send it to Axel and have him rebuild it to MMC2 specification. Super quality and price.